The DemoConsole application in the Winforms repo stops running after convert added MenuItems to other type items then clicking the last 'Type Here'

[MelonWang1]

.NET version

main branch of WinForms repo

Did it work in .NET Framework?

Not tested/verified

Did it work in any of the earlier releases of .NET Core or .NET 5+?

No

Issue description

Actual result:
The DemoConsole application in the Winforms repo stops running after covert added MenuItems to other type items then clicking the last 'Type Here'.

stoprunning.mp4

Expected result:
The DemoConsole application in the Winforms repo running well after covert added MenuItems to other type items then clicking the last 'Type Here'.

Steps to reproduce

1. Run test sample: DemoConsole bases on main branch in Winforms repo.
2. Switch to ToolStripContainer tabpag.
3. Add a MenuItems to ToolStripDropDownButton1.
4. Covert MenuItems to Textbox or other type items.
5. Select 'Type Here' to show last 'Type Here".
6. Click last 'Type Here".

More info:

1. This issue also repo in MenuStrip control, but cannot repro in MenuStrip existing item.

not.repro.mp4

[Tanya-Solyanik]

I guess that a service is missing from the demo console, please identify it.